A number of communications standards are currently available for wireless communications links. In order to keep development costs for the various component groups as low as possible, efforts are made to cover as many communications standards as possible with the smallest possible number of component groups. For example, the most recent base stations for mobile terminal devices, not only operate the Global System for Mobile Communications (GSM) standard but also transmit and receive, for instance, in the frequency range for Universal Mobile Telecommunications System (UMTS) or Long Term Evolution (LTE). Such base stations generate so-called multi-standard radio signals. The development and above all the testing of universal component groups within a base station which uses different communications standards at the same time can be difficult and time-consuming. Often, only the spectral characteristics are measured in one test scenario, and these are used to determine whether the corresponding communications standard has been fulfilled or not.
A method and a device for the operation of a frequency-mask trigger unit is known from EP 2071341 A2. Starting from the spectral characteristic of a signal to be measured, an upper and a lower mask are generated with a spacing distance from the latter. If a signal to be measured overshoots the upper mask and/or the lower mask, an alarm can be triggered. The disadvantage with EP 2071341 A2 is that an automatic analysis of the signal which violates the mask is not possible.
What is needed, therefore, is to provide a solution for the detailed analysis of a communications signal dependent upon its spectral characteristic.